The mysteries of West Nile virus are being uncovered at Colorado State University (CSU), thanks to a joint effort of the United States Equestrian Team (USET), the Centers for Disease Control (CDC), and the United States Department of Agriculture (USDA). West Nile virus, which is a type of encephalitis thought to be spread by the bite of an infected mosquito, appeared in a group of horses in Long Island, N.Y., in the autumn of last year. Studies were to begin immediately, pending approval of the CSU laboratory facility by the USDA.

Richard Bowen, DVM, PhD, associate professor of Biology at CSU, is coordinating the investigation into the virus, which caused the death of 13 out of 22 symptomatic horses. Previously, 39 human cases were confirmed in New York City, and six deaths were attributed to the disease.

“We need to establish a baseline of information by looking at what West Nile does in the horse, how virulent it is, and how much disease causes short- and long-term effects,” said Bowen. This gathering of information of how West Nile behaves in horses and amplified hosts is critical prior to making a vaccine or formulating any type of control strategy.

According to Bowen, nobody knows the likelihood that West Nile will show up again in the eastern United States during mosquito season. “If it establishes, that would accelerate efforts to test vaccines so there would be something for horse owners to use.”

The faculty researchers will be working with West Nile that has been isolated from a dead crow and a dead horse. Twelve equines will be used for the studies, which will be performed in a biocontainment laboratory. The CDC is providing mosquitos for administration of the virus to the study subjects